1. Field of the Invention
The present invention relates to digital cameras and the like. More particularly, the invention relates to an image input device, a photographing device, and a photographing system, which are provided with communicating functions, and to a communication device and a communication system, which perform transmission and reception of images or the like. The invention also relates to a storage medium that stores processing steps readable by a computer for controlling the operations of these apparatuses, devices, or systems.
2. Related Background Art
Along with the technical advancement of semi-conductor and other technology, the spread of digital cameras has been remarkable in recent years. The digital camera digitizes photographed images and stores them in an image memory. For the image memory a semiconductor storage is often used.
However, since semiconductor storage is extremely expensive, there is automatically a limit as to the capacity of the semiconductor storage that can be used in a digital camera in consideration of the overall cost of the digital camera. In other words, the number of photographs that can be taken is limited. At present, the standard capacity of the semiconductor storage provided for a digital camera is not large enough for the photographing frequency usually anticipated for a camera.
Now, for example, there is a digital camera that uses an exchangeable storage device, such as a PCMCIA flash memory card, a smart memory, so that the number of photographs that can be taken by such a camera is increased by allowing the user to exchange the image storage in accordance with his requirement.
Conceivably, however, there may be a case where a new image storage is obtainable when the user wishes to replace the storage that has become full. As a result, the user has to estimate the number of photographs that he may wish to take beforehand, and bring with him a sufficient number of PCMCIA flash memory cards.
Alternatively, in order to provide capacity for a sufficient number of photographs to be taken, it may be possible to use some other media than semiconductor storage, such as a hard disc or other magnetic storage. Nevertheless, even if a magnetic storage is used as the image memory, its capacity is not infinite.
Therefore, the number of photographs that may be taken by the aforesaid digital camera is limited by the capacity of the built-in image storage or the availability of exchangeable storage devices used. Under such circumstances, if pictures cannot be taken on the photographing site in numbers beyond such limit, for example, it is necessary to erase any unwanted pictures that have been taken and stored in the image storage, or else to transfer the stored images to the storage device or the like in a personal computer. With an operation of this kind, it is possible to increase the capacity of the image storage for use.
However, the requirement of such operations as described above that would not be carried out on the photographing site results in the inevitable loss of time, and this becomes a significant drawback in using a digital camera for which immediacy is essential.
More specifically, when an unwanted picture has to be erased from among the images that have been photographed, it is imperative to confirm various pieces of information to determine which one of the images can be discarded. Making such confirmation exactly becomes a great burden on the photographer. In some cases, it is not easy to determine whether or not the photographed image is readily usable through the small display screen generally provided for a digital camera.
Further, in order to enable the aforesaid confirmation to be made efficiently, there is a need to such provision of a new group of operational switches or a display screen dedicated for the confirmation. This may stand in the way of making the digital camera smaller.
Furthermore, it may represent a psychological burden on the photographer if any one of the images that he has taken should be erased on the photographing site, and such an erasure may result in an intense sense of denial.
On the other hand, when the photographed images are transferred to the storage device in a personal computer, such burdens as described above are not imposed upon the photographer, but the interface or the like to perform such transfer between the digital camera and the personal computer must be carried around by the photographer. As a result, the physical burden on him becomes greater.
Here, therefore, in order to solve the above problems, it is conceivable to provide a digital camera with communicating functions, for example, so that the photographed images or electronic mails are transmitted or received as required.
Nevertheless, with a digital camera that may be structured to enable it to perform communications, a collision of requests for access to a memory may occur if one and the same memory is used to store photographed images and the data on transmission and reception. Then, there will be created a new problem that may have not been encountered with a digital camera which is provided only with the photographing functions. For example, if the memory which is intended to be used for the storage of a photographed image should be occupied in receiving data at the very moment the photographer is about to take a picture, photographing is, thus, no longer executable.
In order to avoid a problem of this kind, the photographer is required to determine on the site whether or not such communication should be received at the moment he is notified of a communication call. Then, it becomes impossible to maintain the immediacy of photography, and there is a good possibility that a photo op will be lost eventually. A problem of this kind presents a significant drawback in using a digital camera.
Also, it is conceivable that the reception (received) data is not all stored if the photographing function should operate during communication. This may produce an unfavorable effect on the reliability of communication. As a result, it may also present a significant drawback in using a digital camera which is provided with the communicating function.